> From: Robert Elz <[EMAIL PROTECTED]> > > Date: Wed, 4 Sep 2002 14:39:08 +0300 > From: Markku Savela <[EMAIL PROTECTED]> > Message-ID: <[EMAIL PROTECTED]> > > | I don't see where the two different protocols come from. As explained, > | membership of solicited node multicast group is implicitly indicated > | by EACH packet the node sends. > > This only works if the node actually sends a packet (from that address).
Such node will then only receive linklocal multicast (or is in promiscuous mode) without ever sending anything. Such node doesn't really need address at all, it can even skip the DAD. > I suppose that switches could build a bunch of extra magic, to try and > fathom where to send solicited node multicast packets (which would mean > that it would need to recognise them, which means peering into the L3 > headers of every multicast packet, If it snoops MLD, it has to peek into L3 and deeper (locate ICMP header after potential sequence of extension headers) for every multicast packet anyways. Looking at IPv6 source address is trivial compared to this (it's always in the same fixed position). > The cost is the need to send a packet. That's done normally when adding > a multicast addr to an interface, so the code is there anyway (or should > be) - to not send one when the multicast addr happens to be a solicited > node addr would seem to take extra code (though of course, this kind of > thing tends to depend upon the implementation). Exactly, when implementing IPv6, there was no logical reason to do MLD for link local groups. Additional consideration: if solicited-node groups are true part of MLD, then one should note that MLD query with ANY group will elicit responce from almost every node on the link (as I assume high probability that the solicited node groups usually have only one or few hosts each). How many nodes are on the link? Will some reports be lost? -------------------------------------------------------------------- IETF IPng Working Group Mailing List IPng Home Page: http://playground.sun.com/ipng FTP archive: ftp://playground.sun.com/pub/ipng Direct all administrative requests to [EMAIL PROTECTED] --------------------------------------------------------------------
